Industrial burner



Dec. 7, 1965 F. M. WALL 3,221,797

INDUSTRIAL BURNER Filed NOV. 18, 1963 INVENTOR. FRASER M. WALL ATTORNEY.

United States Patent 3,221,797 INDUSTRiAL BURNER Fraser M. Wall,Abington, Pa., assignor to Selas Corporation of America, Dresher, Pa., acorporation of Pennsylvania Filed Nov. 18, 1963, Ser. No. 324,511 4Claims. (Cl. 158--11) The present invention relates to industrialburners, and more particularly to a burner that is adapted to use gas orlight oils, generally from No. 2 fuel oil to naphtha, as fuel.

It has been difiicult to design burners of the radiant cup type whichuse a liquid fuel because of the tendency of the fuel to burn asdroplets or to produce tongues of flame that burned away from thesurface of the cup, thus reducing its incandescence. This is due, inlarge part, to incomplete vaporization of the fuel and to incompletemixing of the fuel and air prior to the time it is discharged into thecup.

It is an object of the invention to provide a radiant cup-typeindustrial burner that will burn oil with the same characteristics asgas. It is a further object of the invention to provide an industrialburner which will use oil or gas as a fuel interchangeably and with noapparent effect on its combustion characteristics.

In practicing the invention, there is provided a distributing memberwhich projects into the base of a cup-shaped depression of a burnerblock. This distributor has a chamber that is in communication with thedepression by a series of substantially radially directed passages. Fuelin the form of either gas or liquid is discharged into the chamber whereit is mixed thoroughly with combustion air, which preferably is heated.The mixture is dis charged through the passages where it is burned alongthe surface of the cup to heat said surface to incandescence.

The various features of novelty which characterize my invention arepointed out with particularity in the claims annexed to and forming apart of this specification. For a better understanding of the invention,however, its advantages and specific objects attained with its use,reference should be had to the accompanying drawing and descriptivematter in which I have illustrated and described a preferred embodimentof the invention.

In the drawings:

The single figure drawing shows the burner in section.

Referring to that figure, there is shown a furnace wall 1 in which isplaced a burner block 2, of ceramic material having a cup-shapeddepression 3 formed in its face. This block and the wall immediatelybeyond it is provided with a coaxial opening extending from the base ofthe cup to the outer surface of the furnace wall in which is received ametal fuel and air distributor member 4 preferably made of heatresisting alloy. The distributor is cylindrical and has in it a chamber5 the end of which toward the furnace, is closed by an end wall 6. Theaxially extending side wall 7 of the distributor is formed in the shapeof a venturi with the large end terimnating adjacent to the end wall 6and the throat 8 of the venturi being spaced from the end. Chamber 5 isconnected with the burner cup by means of a plurality of radiallyextending passages 9 around the periphery of the distributor. As shownin the drawing, the distributor is snugly received in the opening in thefurnace wall and projects beyond this opening so that passages 9 clearthe surface of the cup 3, thus permitting unobstructed discharge of thefuel mixture from the chamber radially along the surface of cup 3.

Air is supplied to the distributor, and the distributor is held inposition in the burner block, by means of an inlet casting 11 that canbe either straight or in the form 3,221,797 Patented Dec. 7, 1965 of anelbow as shown. The advantage of making the casting 11 in the form of anelbow is one of space in that it does not project far beyond the furnacewall. The casting is provided with a radially extending flange 12 whichis bolted to the metal shell 13 on the furnace wall by means of bolts14. Flange 12 engages a radially extending flange 15 on the outer end ofdistributor 4 to hold the distributor in place in the burner block. Agasket 16 between the shell 13 and an axially extending ridge on flange15 insures accurate alignment of the parts and that no gases can enteror escape around the distributor. A suitable gasket can be used, ifdesired or necessary, between flanges 12 and 15. This constructionpermits parts of the burner to be quickly and accurately assembled andreplaced.

Axially aligned with chamber 5 and throat 8, is a boss 17 formed oncasting 11 to receive the fuel oil supply parts. These parts include aconnector 18 that is threaded into the boss and which receives a supplypipe 19, connected to a suitable oil supply. The other end of connector18 has threaded into it a tube 21 which supports, axially of thechamber, an atomizer 22.

Air is supplied through casting 11, as noted above, and the flow of aircan be controlled by a damper 23 extending across the upper end ofcasting 11. This damper is mounted on a shaft 24 that extends through apacking gland 25 and packing 26 with the outer end having attached to itan adjusting knob 28. The knob can be provided, if desired, withsuitable indicia to indicate the position of the damper and with alocking screw 29 that can be used to hold the damper in any adjustedposition. Air is supplied to casting 11 through a pipe 31 from anysuitable source of supply.

The burner can be used with either liquid or gas as fuel, or acombination of the two. To this end, casting 11 is provided with a gasinlet 32 which is perpendicular to the axis of the casting anddistributor and which is also perpendicular to the air inlet.

In assembling the parts of the burner, the distributor and casting 11are moved together from the outside of the furnace until the distributoris received in the furnace opening as shown. The end wall 6 of thedistributor and passages 9 can be accurately positioned with respect tothe surface of cup 3 by using a gasket 16 of the proper thickness. Inassembling the parts, the distributor is moved into the opening of thefurnace wall until the back edges of passages 9 project slightly beyondthe surface of the cup. The atomizer and its supporting tube 21, whichhave been mounted on connector 18, are then moved into position andthreaded into boss 17. The location of the atomizer axially in thedistributor will depend upon the angle of discharge of spray from theatomizer. The atomizer can ordinarily have a spray varying from about 30to about The atomizer is adjusted axially so that'its cone of spray willstrike the inner surface 7 of chamber 5 at a plane substantiallyperpendicular to the axis of the chamber and slightly to the rear ofpassages 9. The solid line position of the atomizer in the drawingshows, in dotted lines, an atomizer spray of a relatively narrow angle,while the dotted line position of the atomizer shows a spray of arelatively wide angle. It will be noted in both cases that the atomizeris adjusted carefully to an axial location in which the dischargetherefrom will strike the inner surface of the chamber at a pointslightly back of the inner ends of passages 9. This position can bedetermined accurately and a tube 21 of the proper length used to supportthe atomizer. Although any type of atomizer with the proper spray anglecan be used, it is preferred to use a pressure type atomizer in which noatomizing fluid is required for the fuel.

In the operation of the burner, liquid fuel, that can vary from naphthato No. 2 fuel oil, is supplied to the atomizer and is discharged by itinto chamber 5. Air is supplied through pipe 31 to flow through chamber5 and out of openings 9. This air is heated to a temperature sufiicientto vaporize the fuel being used and will vary from about 300 F. fornaphtha to about 700 F. for N0. 2 fuel oil. As the air is introducedthrough pipe 31 and casting 11, it will flow axially through distributor4. Since the cone of oil from atomizer 22 has a direction to strike theinner wall of chamber 5, the air flowing in an axial direction will pickup all of this oil and will vaporize it so that a mixture in the form ofvapor and air is discharged across the surface of the cup. Throat '8 ofthe venturi section, with the subsequent enlargement of the chambersection, gives a pressure change to the air and suflicient turbulence sothat the air is mixed thoroughly with the atomized oil. The fuelmixture, in the form of air and vaporized oil, discharged throughpassages 9 can be ignited and will burn with the characteristics of gasas it is flowing across the surface of the cup-shaped depression 3 inorder to heat the surface to incandescence. Heat is, therefore, suppliedby the burner, both in the form of radiant heat from the cups surface asWell as the hot products of combustion. When the burner has beenoperating a short time, end wall 6 will be heated to a point where itwill radiate heat back into chamber 5 in order to assist in thevaporization of the oil that is being discharged from the atomizer.Suflicient heat is radiated back into the chamber so that when theburner is operating the temperature of the air supply does notnecessarily have to be quite as high as would otherwise benecessary inorder to vaporize the fuel.

In order for the burner to work best, it is necessary to supply fuel andair in stoichiometric proportions. This can be accomplished with anyconventional control mechanism which, in this case, would preferably beresponsive to pressure of the air and of the fuel From time to timeadjustments can be made to the air pressure-by adjusting the position ofdamper 23. These adjustments may be necessary as the temperature of theair is varied. In addition, if for some reason it is desired to shutoffone burner of a number of burners, damper 23 can be closed for thispurpose as well as to permit theremoval of the atomizer for cleaning orreplacement without shutting down the rest of the furnace.

As noted above, the burner can also be used with gas as a fuel. To thisend, a gas supply is introduced into casting 11 through opening 32 thatis at right angles to the axis of the distributor as well as to thesupply of air. This arrangement insures that there will be enoughturbulence produced in the casting and the distributor to insurecomplete mixing of the fuel and air prior to the time it isdischargedthrough passages 9. It is noted that whether the fuel is liquid or gas,or a combination of the two, the flow of this fuel through thedistributor is sufficient to cool end wall 6 enough so that it will atall times be at a temperature below that which an alloy steel cansatisfactorily stand.

From the above it will be seen that I have provided an oil or an oil andgas burner which is simple in construction, easily installed andrepaired, and one which will burn oil with the characteristics of a gas,

While in accordance with the provisions of the statutes I haveillustrated and described the best form of embodiment of my inventionnow known to me, it will be apparent to those skilled in the art thatchanges may be made in the form of the apparatus disclosed withoutdeparting from the spirit and scope of the invention set forth in theappended claims, and that in some cases certain features of my inventionmay be used to advantage without a corresponding use of other features.

What is claimed is:

1. In a burner, the combination of a hollow, cylindrical distributormember having a closed end to form a chamber therein, said member beingprovided with a plurality of substantially radial passages extendingfrom said chamber adjacent to said end to the exterior of said member,the interior of said chamber having the shape of an unobstructed venturiwith the large end thereof terminating at said passages and the throatthereof being spaced from said end of said chamber, a liquid fuelatomizer having a predetermined angle of spray, means to mount saidatomizer adjacent to said throat and centrally of said chamber anddirected axially toward said closed end, said atomizer being located adistance from said closed end such that the spray from the atomizer willstrike the interior of said chamber adjacent to said large end of saidventuri and the edges of said passages, and means to supply combustionair axially to said chamber from a location upstream of said atomizerwhereby said combustion air will cross the spray of atomized fuel to mixtherewith prior to being discharged through said passages.

2. The combination of claim 1 in which said means to supply combustionair terminates at said distri-butor in a passage axially aligned withsaid chamber, and means to supply fuel gas to mix with air flowing insaid last mentioned passage, said fuel gas supply means directing thefuel gas into said passage at an angle to the flow of air therethrough.

3. The combination of claim 1 in which said closed end of saiddistributor is of metal to radiate heat to said chamber.

4. The combination of claim 1 in which said means to supply combustionair to said distributor includes a part having a passage therein for theair which terminates at said chamber, and adjustable damper means tovary the opening of said passage.

References Cited by the Examiner UNITED STATES PATENTS 2,292,664 8/1942Schwartz 158-76 2,333,531 11/1943 Ferguson 158-11 2,821,246 1/1958 Ideet a1. 158-11 2,980,171 4/1961 Furceyk et a1 158-11 3,000,435 9/1961Bloom et a1. 158-11 FOREIGN PATENTS 27,183 1910 Great Britain. 328,3148/1935 Italy.

FREDERICK L. MATTESON, 111., Primary Examiner.

MEYER PERLIN, JAMES W. WESTHAVER,

Examiners.

1. IN A BURNER, THE COMBINATION OF A HOLLOW, CYLINDRICAL DISTRIBUTORMEMBER HAVING A CLOSED END TO FORM A CHAMBER THEREIN, SAID MEMBER BEINGPROVIDED WITH A PLURALITY OF SUBSTANTIALLY RADIAL PASSAGES EXTENDINGFROM SAID CHAMBER ADJACENT TO SAID END TO THE EXTERIOR OF SAID MEMBER,THE INTERIOR OF SAID CHAMBER HAVING THE SHAPE OF A UNOBSTRUCTED VENTURIWITH THE LARGE END THEREOF TERMINATING AT SAID PASSAGES AND THE THROATTHEREOF BEING SPACED FROM SAID END OF SAID CHAMBER, A LIQUID FUELATOMIZER HAVING A PREDETERMINED ANGLE OF SPRAY, MEANS TO MOUNT SAIDATOMIZER ADJACENT TO SAID THROAT AND CENTRALLY OF SAID CHAMBER ANDDIRECTED AXIALLY TOWARD AND CLOSED END, SAID ATOMIZER BEING LOCATED ADISTANCE FROM SAID CLOSED END SUCH THAT THE SPRAY FROM THE ATOMIZER WILLSTRIKE THE INTERIOR OF SAID CHAMBER ADJACENT TO SAID LARGE END OF SAIDVENTURI AND THE EDGES OF SAID PASSAGES, AND MEANS TO SUPPLY COMBUSTIONAIR AXIALLY TO SAID CHAMBER FROM A LOCATION UPSTREAM OF SAID ATOMIZERWHEREBY SAID COMBUSTION AIR WILL CROSS THE SPRAY OF ATOMIZED FUEL TO MIXTHEREWITH PRIOR TO BEING DISCHARGE THROUGH SAID PASSAGES.